BikeBeamer Adds POV Display To Bicycle Wheels

June 11, 2024 by Bryan Cockfield 16 Comments

Unless you’re living in a bicycle paradise like the Netherlands, most people will choose to add some sort of illumination to their bicycle to help drivers take note that there’s something other than a car using the road. Generally, simple flashing LEDs for both the front and the rear is a pretty good start, but it doesn’t hurt to add a few more lights to the bicycle or increase their brightness. On the other hand, if you want to add some style to your bicycle lighting system then this persistence of vision (POV) display called the BikeBeamer from [locxter] might be just the thing.

The display uses four LED strips, each housed in their own 3D printed case which are installed at 90-degree angles from one another in between the spokes of a standard bicycle wheel. An ESP32 sits at the base of one of the strips and is responsible for storing the image and directing the four displays. This is a little more complex than a standard POV display as it’s also capable of keeping up with the changing rotational speeds of the bicycle wheels when in use. The design also incorporates batteries so that no wires need to route from the bike frame to the spinning wheels.

This is an ongoing project for [locxter] as well, meaning that there are some planned upgrades even to this model that should be in the pipe for the future. Improving the efficiency of the code will hopefully allow for more complex images and even animations to be displayed in the future, and there are also some plans to improve the PCB as well with all surface-mount components. There are a few other ways to upgrade your bike’s lighting as well, and we could recommend this heads-up headlight display to get started.

How To Cram 945 LEDs Into A Teeny Tiny Vegas-Style Sphere

May 31, 2024 by Donald Papp 18 Comments

[Carl Bugeja] finds the engineering behind the Las Vegas Sphere fascinating, and made a video all about the experience of designing and building a micro-sized desktop version. [Carl]’s version is about the size of a baseball and crams nearly a thousand RGB pixels across the surface.

A four-layer flexible PCB is the key to routing data and power to so many LEDs.

Putting that many addressable LEDs — even tiny 1 mm x 1 mm ones — across a rounded surface isn’t exactly trivial. [Carl]’s favored approach ended up relying on a flexible four-layer PCB and using clever design and math to lay out an unusual panel shape which covers a small 3D printed geodesic dome.

Much easier said that done, by the way. All kinds of things can and do go wrong, from an un-fixable short in the first version to adhesive and durability issues in later prototypes. In the end, however, it’s a success. Powered over USB-C, his mini “sphere” can display a variety of patterns and reactive emojis.

As elegant and impressive as the engineering is in this dense little display, [Carl] has some mixed feelings about the results. 945 individual pixels on such a small object is a lot, but it also ends up being fairly low-resolution in the end. It isn’t very good at displaying sharp lines or borders, so any familiar shapes (like circles or eyes) come out kind of ragged. It’s also expensive. The tiny LEDs may be only about 5 cents each, but when one needs nearly a thousand of them for one prototype that adds up quickly. The whole bill of materials comes out to roughly $250 USD after adding up the components, PCB, controller, and mechanical parts. It’s certainly a wildly different build than its distant cousin, the RGB cube.

Still, it’s an awfully slick little build. [Carl] doubts there’s much value in pursuing the idea further, but there are plenty of great images and clips from the build. Check out the video, embedded below.

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Play Giant Tetris On Second-Floor Window

May 28, 2024 by Bryan Cockfield 11 Comments

Sometimes it seems like ideas for projects spring out of nothingness from a serendipitous set of circumstances. [Maarten] found himself in just such a situation, with a combination of his existing Tetris novelty lamp and an awkwardly-sized window on a second-floor apartment, he was gifted with the perfect platform for a giant playable Tetris game built into that window.

To make the giant Tetris game easily playable by people walking by on the street, [Maarten] is building as much of this as possible in the browser. Starting with the controller, he designed a NES-inspired controller in JavaScript that can be used on anything with a touch screen. A simulator display was also built in the browser so he could verify that everything worked without needing the giant display at first. From there it was on to building the actual window-sized Tetris display which is constructed from addressable LEDs arranged in an array that matches the size of the original game.

There were some issues to iron out, as would be expected for a project with this much complexity, but the main thorn in [Maarten]’s side was getting his controller to work in Safari on iPhones. That seems to be mostly settled and there were some other gameplay issues to solve, but the unit is now working in his window and ready to be played by any passers-by, accessed by a conveniently-located QR code. Tetris has been around long enough that there are plenty of unique takes on the game, like this project from 2011 that uses Dance Dance Revolution pads for controllers.

POV Digital Clock Is The Literal Sands Of Time

May 9, 2024 by Dan Maloney 9 Comments

Sand has been used to keep track of the passage of time since antiquity. But using sand to make a persistence of vision digital clock (English translation) is something altogether new. And it’s pretty cool, too.

The idea behind the timepiece that [Álvaro Gómez Giménez] built is pretty simple drop a tiny slug of fine sand from a hopper and light it up at just the right point in its fall. Do that rapidly enough and you can build up an image of the digits you want to display. Simple in concept, but the devil is in the details. Sand isn’t the easiest material to control, so most of the work went into designing hoppers with solenoid-controlled gates to dispense well-formed slugs of sand at just the right moment. Each digit of the clock has four of these gates in parallel, and controlling when the 16 gates open and close and when the LEDs are turned on is the work of a PIC18F4550 microcontroller.

The build has a lot of intricate parts, some 3D printed and some machined, but all very carefully crafted. We particularly like the big block of clear plastic that was milled into a mount for the main PCB; the translucent finish on the milled surfaces makes a fantastic diffuser for the 96 white LEDs. The clock actually works a lot better than we expected, with the digits easy to make out against a dark background. Check it out in the video below.

Between the noise of 16 solenoids and the sand getting everywhere, we’d imagine it wouldn’t be a lot of fun to have on a desk or nightstand, but the execution is top-notch, and an interesting and unusual concept we haven’t seen before. Sure, we’ve seen sandwriting, but that’s totally different. Continue reading “POV Digital Clock Is The Literal Sands Of Time” →

Boneblocker Is A Big LED Wall That Rocks

April 28, 2024 by Lewin Day 3 Comments

[Nick Lombardy] took on a job almost every maker imagines themselves doing at some point. He built a giant LED wall and he did a damn fine job of it, too. Introducing BoneBlocker.

BoneBlocker is an 8 x 14 wall of glass blocks that lives at a bar called The Boneyard. Each block was given a length of WS2812B LED strip. 30 LED/meter strips were chosen, as initial maths on the 60 LED/meter strips indicated the whole wall would end up drawing 1.5 kW. Discretion, and all that.

The whole display is run from a WT32-ETH01 board, which is a fast ESP32-based module that has onboard Ethernet to boot. [Nick] used the WLED library as he’d seen others doing great things with it, performance-wise. He ended up using one board per column to keep things fast, but he reckons this was also probably a little bit of overkill.

His article steps through the construction of the wall, the electronics, and the software required to get some games working on the display. The final result is quite something. Perhaps the best bit is his explanation of the custom controller he built for the game. Dig into it, you won’t be disappointed.

In particular, we love how the glass blocks elevate this display to a higher aesthetic level. We’ve seen other great projects tread this same route, too. Video after the break.

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Solar Panel Keeps Cheap Digital Calipers Powered Up

April 20, 2024 by Dan Maloney 40 Comments

There’s no doubt that cheap digital calipers are useful, especially when designing 3D-printed parts. Unfortunately, cheap digital calipers are also cheap, and tend to burn through batteries quickly. Sure, you can remove the battery when you’re done using them, but that’s for suckers — winners turn to solar power to keep their calipers always at the ready.

[Johan]’s solar upgrade begins with, unsurprisingly, a solar cell, one that just fits on the back of his digital calipers. Like most of these cheap calipers, this one is powered by a single 1.5 V LR44 button cell, while the polycrystalline solar cell is rated for 5 V, so [Johan] used a red LED as a crude voltage regulator. He also added a stack of fourteen 100 μF SMD capacitors soldered together in parallel. The 1206 devices form a 1,400 μF block that’s smaller than the original button cell so that everything fits in the vacated battery compartment. It’s pretty slick.

Given their agreeable price point, digital calipers are a tempting target for hacking. We’ve seen a ton of them, from accessibility add-ons to WiFi connectivity and even repurposing them for use as DROs. Ever wonder how these things work? We’ve looked at that, too.

Lamp Becomes Rotating, Illuminated Sign For Festival Table

April 2, 2024 by Donald Papp 5 Comments

Two things we love are economical solutions to problems, and clever ways to use things for other than their intended purpose. [CelGenStudios] hits both bases with a simple illuminated and spinning sign made from a lamp and a couple economical pieces of hardware: an LED bulb, and a solar-powered product spinner. Both are readily and cheaply available from your favorite overseas source.

The first step in making a cheap illuminated sign is to not buy one, but instead make do with a standing lamp. Plug a bright LED bulb into the socket, decorate the lampshade with whatever logos or signs one wishes to display, and one has an economical illuminated sign suitable for jazzing up a table at an event. But what really kicks it up a notch is making it rotate, and to do that is where the clever bit comes in.

Mounting the lampshade to the solar turntable body yields a simple, rotating, illuminated sign.

The first attempt used a BBQ rotisserie motor to turn the whole lamp, but it was too loud and not especially stable. The second attempt used a “disco ball effect” LED bulb with a motorized top; it worked but turned too quickly and projected light upward instead of into the lampshade.

The winning combination is LED bulb plus a little solar-powered turntable onto which the lampshade mounts. As a result, the lampshade spins slowly when the lamp is turned on. It might not be the most durable thing to ever come out of a workshop, but as [CelGenStudios] says, it only needs to last for a weekend.

The basic concept is far more simple than it might sound, so check it out in the video (embedded below) to see it in action. Curious about what’s inside those little solar spinners? Skip to 5:55 in the video to see how they work. And if you’re intrigued by the idea of using solar power for motive force but want to get more hands-on with the electrical part, we have just the resource for turning tiny motors with tiny solar cells.

Thanks to [Bike Forever] for the tip!

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